This invention relates to a conical brake assembly that permits more lining material to be packaged in a brake drum than in a conventional cylindrical brake drum assembly, while reducing actuation energy requirements
Vehicle brake assemblies typically include brake linings that interact with either a brake drum to brake a vehicle. The brake linings are supported on plates and are controlled by actuators, which bring the linings into contact with the brake drum, utilizing frictional forces to stop or slow a vehicle.
These linings wear over time due to the frictional contact. For heavy duty braking applications, the linings wear out quickly and need to be replaced often. This is very expensive and results in significant vehicle down time.
Another disadvantage with brake linings is that as the linings wear, the brake becomes out of adjustment. Thus, the necessary brake pedal stroke length to actuate the brake will increase as the linings wear. To account for this, brake assemblies include slack adjusters that adjust the position of the brake linings to try to keep a constant distance between the surface of the linings and the brake drum or disc surface. These slack adjusters take up valuable packaging space and increase assembly time and cost.
Thus, it is desirable to provide a braking assembly that allows a greater amount of brake lining material to be packaged within the drum while and which utilizes an adjuster that overcomes the above mentioned deficiencies.
In a disclosed embodiment of this invention, a brake assembly includes a brake drum that is mounted for rotation about an axis. The brake drum has a conical interior cavity that defines a braking surface. A conical brake lining assembly mounted to a non-rotating axle component and presents a friction surface. A brake actuator moves the friction surface into engagement with the braking surface to brake a vehicle.
In a preferred embodiment, the brake assembly includes an adjuster mechanism that maintains a predetermined distance between the brake drum and lining assembly. The adjuster includes a first member having a threaded inner bore and a conical exterior surface. The adjuster also includes a second member having a threaded inner bore and a conical exterior surface. The first and second members are mounted on a common shaft having a threaded exterior surface. One of the threaded bores has a right handed thread and the other threaded bore has a left handed thread. The right and left handed threads engage the threaded exterior surface of the shaft to selectively draw the first and second members together linearly along the shaft to force the brake linings outwardly to maintain the predetermined distance.
This configuration allows more brake lining material to be packaged within the drum and provides a more efficient brake assembly.
These and other features of the present invention can be best understood from the following specification and drawings, the following of which is a brief description.